Field of the Invention
This invention relates to the field of pipeline maintenance and more specifically to the field of using pipeline pigs for pipeline maintenance and new construction.
Background of the Invention
Pipeline pigs are conventionally used in the maintenance of pipelines. Pipeline pigs are typically inserted into a pig launcher. Pressure may then be added that pushes the pipeline pig along the pipeline until it reaches a pig receiver for removal from the pipeline. The pipeline pigs are commonly used to remove foreign material that may be in the line during construction of new pipelines. The pipeline pigs may also be used to make sure the pipeline has not become dented or wrinkled during bending or laying as well as also used to check for the ovalness of the pipeline. Further uses of the pipeline pigs may include removing water from pipelines after hydrostatic tests.
Drawbacks to conventional pig receivers include harm to the environment. For instance, matter removed from the pipelines may not be properly contained. Additional drawbacks to conventional pig receivers include downtime in launching new pipeline pigs when other pipeline pigs are being removed from the pipeline.
Further drawbacks include that when retrieving one pipeline pig at a time from a pipeline, such retrieval may be slow and cumbersome. Frequently, removing a single pipeline pig may lead to a large amount of fluid loss. Such fluid loss may occur when using fluid to move the pipeline pig past a gate valve, which may lead to an increase in hazardous fluids falling off the pipeline pig and into the environment during the pipeline pig removal process.
Consequently, there is a need for an improved pig receiver that allows pipeline pigs to be continually launched and received in pipelines. Further needs include improved pig receivers that facilitate environmental concerns.